Rotary toothbrush



3 Sheets-Sheet 1 A. F. ERRINGTON ET AL ROTARY TOOTHBRUSH Filed May 18, 1932 Dec. 20, 1932.

Dec. 20, 1932. A. F. ERRINGTON ET AL ROTARY TOOTHBRUSH s sheets-sheet 2 Filed May 18, 1952 ATTORNEYS Dec. 20, 1932-.

A. F. ERRINGTON ET AL ROTARY TOOTHBRUSH Filed May 18, 1932 5 Sheets-Sheet 5 ATTORNEYS Patented Dec. 2G, 1932 UNITED STATES PATENT OFFICE .ALLISON F. EBRINGTON AND GEORGE L. HEADLEY, OF AKRON, OHIO ROTARYv TOOTHBRUSH Application led May 18,

This invention relates to rotary tooth brushes, and more especially it relates to power driven rotary tooth brushes in which the direction of rotation of. the brush is reversed at regular intervals.

The chief object of the invention vis to provide a tooth brush that will effect an improved and thorough cleansing of the teeth; and to provide a power driven tooth brush the upper and lower sets of teeth, and on each side of both sets. A more specific object is to provide a rotary tooth brush having means for automatically reversing the direction of rotation of the brush at regular intervals. Of the accompanying drawings, l Figure 1 is a front elevation, partly in section, of the improved rotary tooth brush, in its preferred form;

Figure/'2 is an elevation of aconnection by which a tooth brush is connected to the driving means;

Figure 3 is a section thereof on the line 3-3 of Figure 1, on a larger scale;

Figure 4 is a section on the line 4 4 of Figure 1; Figure 5 is a section on the line 5 5 of Fi ure l;

igure' is a front elevation of anotherl embodiment ofthe invention; and

Figure 7 is a section on the line 7 7 of Fi ure 6.

eferring to the drawings,vA designates generally a power unit, B is a rotary tooth brush, and C is aiexible connection for transl mitting rotary motion from the power unit to the tooth brush. The brush B is readily detachable from the connection C so that any number of brushes may be used with a single power unit.

The power unit is housed in a receptacle comprising a base or back-plate 10 that may be secured to'the wall by cap-screws 1l or the like, and a box-like cover 12 that is removably secured to the back-plate by screws 13, 1'3.

that will operate in the same manner upon 1932. seriai No. 612,088.

Preferably the back-plate 10 has a depending extension 14 that is forwardly bent and formed with a plurality of suitably shaped slots or recesses 15, 15in its free edge for receiving and supporting respective. tooth `50 22 that is mounted upon the back-plate 10.

The gear 20 carries a wrist-pin 23 that is eci centrically positioned and extends from one lateral face of the gear, and connected to said '85 wrist-pin is one end of a pitman 24, the other end of which is pivotally connected to one end of a rack 25. Opposite lateral faces of the rack 25 are formed with respective longitudinal /grooves 26, which grooves accommodate respective ribs 27 formed on adjacent faces of a centrally recessed bracket 28 that is mounted upon the base-plate l0, said ribs constituting slideways for the rack 25. The rack 25 is meshed with a pinion 29 that is keyed to a 'I5 shaft 30 that is journaled in a suitable bearing-31 formed upon the bracket 28, a portion of said bearing and the shaft 30 projecting through an aperture 32 in the receptaclecover l2. A switch 33 for controlling the elec- 80 trical motor 18 may be mounted at any convenient place on the exterior ofthe cover 12. Attached to the bearing 31 and shaft 30 is the flexible connection C. The latter comprises the usual flexible drive shaft 35, a tubular, iiexible armor or cover 36, and a braided sheath 37 over said armor, the drive shaft fitting loosely Within said armor. One end of the armor structure is provided with a threaded nipple 38 that is threaded into the 90 bearing 31. The same end of the flexible shaft 35 is provided with an apertured {ixa ture 39 that engages the end of the shaft 30 with a tongue and groove connection and is secured thereto by a pin 40 extending through its aperture. The other end of the armor structure is provided with a threaded nipple 42 that is threaded into one end of a tubular sleeve 43, the other end of the latter being formed with a pair of diametrically opposed bayonet slots 44, 44. Within the sleeve 43 the end of the fiexible shaft 35 is provided with a cylindrical fixture 45 that is formed with a diametric rib or tongue 46.

The brush B comprises a tubular casing or handle 48 within which is journaled a shaft 49 that projects from both ends of the casing, and on one of said projecting end portions carries a brush comprising several circumferential rows of radially projecting tufts of bristles 50. A cup-shaped guard 51 is threaded onto the adjacent end portion of the casing 48 and covers the bristles on one side of the brush. The other end of the casing is provided with two radial studs 52, 52 that project therefrom at diametrically opposite points. The end of the shaft 49 remote from the brush is provided with a cylindrical fixture 54 that is formed with two diametric end-slots 55, 55 arranged at right angles to each other. A bushing 56 of libre or other suitable material is disposed between the fixture 55 and the adjacent end of the casing 48. The arrangement is such that the brush casing 48 may be attached to the flexible connection C by inserting the end of the casing into the sleeve 43 and locking it therein by means of the studs 52 and bayonet slots 44. In this position of the casing the tongue 46 of the fixture 45 will interiit one of the slots of the fixture 54 and thus provide driving connection between the drive shaft 35 and the brushshaft 49.

, In the operation of the brush structure, the motor 18 rotates continuously inl one directionandthrough the medium of the pitman 24, effects reciprocating rectilinear movement of the rack 25. This movement of the rack causes rotary movement of the pinion 29 and shaft 30, and the direction of said movement is periodically reversed by the respective back' In addition, the brush is periodically rotated in the opposite direction with the re sult that it will dislodge from between the teeth any particles that may have been wedged therein by the opposite rotation of the brush.

The brush B is easily and quickly connected and disconnected from the flexible connection C, so that but a single power unit A is required for any number of individual brushes.

The embodiment of the invention shown in Figures 6 and 7 is similar to the previously described embodiment, the difference residing in the means provided for rotating the brush alternately in opposite directions. The power unit, designated A', comprises a receptacle consisting of a base-block 60 of wood or other suitable material and a metallic cover 61 mounted thereupon by screws 62, 62 or the like. Within the receptacle is a reversible motor 63 that is mounted upon the base-block 6() and has its shaft 64 directconnected to a threaded shaft 65 that is journaled in bearing brackets 66, 67 that are mounted in the receptacle upon the baseblock 60. Mounted uponl the threaded shaft 65 is a nut 68 that has a bifurcated portion 68a straddling a Guide rod 69, the latter being parallel to said s iaft and being supported by the bearing brackets 66, 67. The arrangement is such that rotation of the shaft. 65 will move the nut 68 longitudinally thereof.

Mounted in the base-block 60 is a reversing switch 70 of any known or preferred construction, and said switch is provided 72 that extends laterally from the -nut and projects through a slot- 7 3 formed in the free end of the lever 71. A manually operated main switch 74 is mounted in a convenient place of the outside of the cover 61. The arrangement is such that when the switch 74 is thrown to on or operative position, the motor 63 is caused to rotate the shaft 65 whereby the nut 68 is moved longitudinally. At the two positions of the nut, indicated by the full and the broken lines in Figure 7, the lever 71 snaps the switch 70 to reversing position, and thus reverses the direction of rotation of the'motor 63. This causes the `shaft 65 to feed the nut 68 in reverse direction, which continues until the switch 70 is again reversedv at the other end of the nuts course.

The bracket 67 and an end of the shaft 65 extend through an aperture 75 in the cover 61, and attached to said bracket and shaft is a exible connection C that may be iden-- tical to the connection C of the previously described embodiment. A brush B similar to the brush B is connected to the free end of the fiexible connection C. The brushing action is the same in both embodiments of the invention except that the brush of the embodiment shown in Figures 6 and 7 does not reverse its direction of rotation as frequently as does the other embodiment yof the invention.

The device' may `be otherwise modified without departing from the spirit of the in- 5 vention or the scope of the appended claim.

What is claimed is:

In a device of the character described, the combination of a rotary tooth brush, a motor for imparting rotary movement thereto, and automatic means for periodically reversing'the direction of said rotary movement.

` ALLISON F. ERRINGTON.

GEORGE L. HEADLEY. 

